Improved expanding-tool



UNITED STATES PATENT OEEICE.

JOHN ORITOHLEY, OF PORTSMOUTH, NEW HAMPSHIRE.

INI PROVED EXPANDING-TOOL.

Specification forming part of Letters Patent No. 51,563, dated December 19, 1865.

To all whom it may concern Be it known that I, JOHN GRrrcIILEY, of Portsmouth, inthe county of Rockingham and State of New Hampshire, have invented a new and useful Improvement in Expanding-Tools;

and I do hereby declare that the following is a full, clear, and exact description thereof, which will enable those skilledin the art to make and use the same, reference being had to the accompanying drawings, forming part ot' this specification, in which- Figure 1 represents a side elevation of this invention. Fig. 2 is a longitudinal central section ot' the same, taken in the plane indicated by the line :c a', Fig. 3. Fig. 3 is a transverse section of the same, the line y y, Fig. 2, indicating the plane of section.

Similar letters of reference indicate corresponding parts.

This invention relates to a tool which can be used as a mandrel or for reamin g, tapping, boring, and other work.

It consists of a cylindrical stock with three or more tapering grooves cut in its surface parallel to its axis, in combination with keys titting into said grooves, and with nuts applied to the ends of the stock and bearing on the ends of the keys or cutters in such a manner that by unscrewing one of the nuts and screwing upV the other the keys or cutters are caused to slide in the tapering grooves, and consequently to expand orcontract radially, and an expanding mandrel, reamer, tap, or other tool is obtained of great practical convenience.

A represents the stock of my tool, which is provided wit-h tive (more or less) tapering grooves, c .cut in parallel to the axis ofthe cylindrical stock. These grooves are intended to receive the keys or cutters b, which are also made tapering, as shown in Fig. 2, and thc ends of which are beveled off and made to t the conntersunk nuts c. These nuts screw on the ends of the stock A, and by unscrewing one and screwing up the other the keys or cutters are caused to slide in the grooves and the tool is expanded or contracted.

The great convenience ot this tool as a man-Y drel for turning, or as a reamer, (if, instead of the keys, cutters are used,) or as a tap will be apparent to every practical mechanic, and requires no further explanation.

I claim as new and desire to secure by Letters Patent- The expandingtool herein described, consisting of the stock A, provided with the radial grooves a, the nuts c, and keys or cutters b, all constructed and arranged in the manner amltor the purpose specified.

JOHN CRITCHLEY.

Witnesses:

WILLIAM CARTLIDGE, Jr., WILLIAM CRI'rcHLEY, Jr. 

